Putative Echinoderm Fossil Cotyledion from Chengjiang Biota

Description: This is an example of the incredible diversity of early life known from the Chengjiang Biota. The diversity of soft-tissue fossils is astonishing: algae, medusiforms, sponges, priapulids, annelid-like worms, echinoderms, arthropods (including trilobites), hemichordates, chordates, and the first agnathan fish make up just a small fraction of the total. Numerous problematic forms are known as well, some of which may have represented failed attempts at diversity that did not persist to the present day. While some researchers place this one in the Problematica, others believe it is an early echinoderm much like the crinoids to come later. The calyx-like cap and stem are indeed evocative of such an assignment, perhaps more than some sort of convergent evolution. Whatever the correct assignment, this is a most unusual example.

Also see: Chengjiang Biota List Chengjiang Fossils